Method and apparatus for detecting smoke and smothering a fire

ABSTRACT

A fire in an enclosed space in an aircraft is, for example, visually detected early since smoke generated by a beginning fire is initially permitted to escape from the enclosed space. The enclosed space is, for example, an overhead luggage bin or a goods container holding food or freight. The smoke can pass through a flow passage either in the form of a gap or a leak between a lid and walls, or between a door and a door frame, or between walls and other walls joined together. Intumescent material is installed along the gaps or leaks and expands into the gaps or leaks when the fire has generated a temperature sufficient for causing the expansion of the intumescent material. Preferably a guide surface assures that the intumescent material expands into the gaps and leaks and cannot expand away from gaps and leaks.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is related to our copending application entitled“Method And Apparatus For Fighting A Fire In An Enclosed Space In AnAircraft”, filed on the same date as the present application. The entiredisclosure of the related application is incorporated herein byreference.

PRIORITY CLAIM

[0002] This application is based on and claims the priority under 35U.S.C. §119 of German Patent Application 103 18 975.0, filed on Apr. 26,2003, the entire disclosure of which is incorporated herein byreference.

FIELD OF THE INVENTION

[0003] The invention relates to a method for visually detecting smokeleaking out of an enclosed space in an aircraft. The invention alsorelates to an apparatus for smothering the fire that generated thesmoke.

BACKGROUND INFORMATION

[0004] Enclosed spaces such as overhead luggage compartments in apassenger cabin ceiling or goods containers for food and freight in theloading space of an aircraft, are conventionally not sealed in anairtight manner so that any fires that might start in these enclosedspaces would be automatically smothered. Rather, leaks in the form ofair flow passages, gaps and openings admit air and thus oxygen into theenclosed space thereby fueling the fire. That is a disadvantage.However, such leaks have the advantage that an early detection of a fireis possible because smoke generation is most intense at the beginning ofa fire and the smoke can escape through these leaks, whereby an earlyvisual detection is possible. The supply of air and thus oxygen appliesparticularly to overhead luggage compartments or bins and to containersthat may be stored in a galley area or in the freight space of anaircraft. Fires that have started in these enclosed spaces have beenknown to expand with detrimental effects into the passenger cabin orinto the freight space of an aircraft.

[0005] UK Patent Publication GB 2,107,182 A discloses various types oflouvers for covering openings in buildings and in doors of buildings forair ventilation. These louvers are constructed with slats, the back sideof which is coated with intumescent material for closing off the airflow channels formed between neighboring slats of the louver when theintumescent material is exposed to elevated temperatures sufficient tocause the intumescent material to expand. Since the expansion isuncontrolled, particularly with regard to the direction of expansion itis not always assured that the cross-sectional flow areas between twoneighboring slats are completely sealed off. Thus, some air could stillpass through the louvers.

[0006] German Patent Publication DE 36 12 377 A1 discloses a fireprotection sealing tape in which a tape material is combined with one ormore intumescent fire protection strands. The intumescent strands whichexpand their volume in response to a respective expansion temperature,are combined with the tape material in such a way, that the expansion ofthe intumescent material will expand the adhesive tape. These tapes haveat least one adhesive outer surface. One or more intumescent materialstrands may be completely embedded in the tape material. Anotherconventional adhesive tape has a strand or strip of intumescent materialpositioned between two strips of tape material. The adhesive tapecombined with an intumescent material strand or strands is installed injoints between neighboring sections of steel reinforced ceilings, walls,slots between lightweight construction walls, concrete ceilings andgenerally in gaps that must be closed. The main purpose of theseconventional adhesive tapes is to prevent a fire that has started in oneroom from moving into neighboring rooms.

[0007] UK Patent Publication GB 2,277,871 A discloses a fire-resistantcontainer in which a metal casing and its metal door are lined on theinside with layers of an intumescent adhesive, a heat resistant thermalinsulating material, and an intumescent strip. The fire-resistantcontainer is for example used to protect filing cabinets against a fire.

[0008] The above described conventional use of intumescent materials,particularly intumescent strips or strands or tapes, leaves room forimprovement particularly for effectively using such materials in anaircraft.

OBJECTS OF THE INVENTION

[0009] In view of the above it is the aim of the invention to achievethe following objects singly or in combination:

[0010] to provide a method that permits simultaneously an early smokedetection and a fire smothering or even extinguishing the fire, in anenclosed space inside the body of an aircraft;

[0011] to automatically seal an enclosed space in an aircraft inresponse to the occurrence of a temperature that will cause anintumescent material to expand inside the enclosed space; and

[0012] to at least initially guide the expansion direction of theintumescent material to substantially or completely seal the enclosedspace in an aircraft, to significantly reduce or even prevent theentrance of air in the enclosed space in which a fire has started.

SUMMARY OF THE INVENTION

[0013] A method for detecting smoke and smothering a fire in an enclosedspace inside an aircraft is characterized according to the invention bythe following steps:

[0014] a) providing at least one air flow passage for air to flow intoand out of said enclosed space for letting smoke, generated by abeginning fire, out of said enclosed space for visual detection of thesmoke outside said enclosed space,

[0015] b) installing in said enclosed space a fireproof or fireintumescent material next to and along said at least one air flowpassage, said fireproof or fire-resistant intumescent material having anexpansion temperature response characteristic higher than a smokecausing temperature in said enclosed space, and

[0016] c) heating said fireproof or fire-resistant intumescent materialat least to said expansion temperature for expanding said fireproof orfire-resistant intumescent material into said at least one air flowpassage for substantially sealing said at least one air flow passagethereby substantially stopping air and oxygen access to said enclosedspace to smother said fire.

[0017] The terms “fireproof” and “fire resistant” are used synonymously.The term “substantially” means that air access has been reducedsufficiently to smother the fire even though air flow has not beenclosed off completely.

[0018] According to the invention there is further provided an aircrafthaving a body enclosing a first space in which there is a secondenclosed space such as an overhead luggage compartment or a containerfor goods such as foods or freight. The enclosed second space has anopening and a lid or door to cover the opening. At least one flowpassage or gap or leak is provided for permitting smoke to pass out ofthe enclosed second space when a beginning fire generates smoke insidethe enclosed second space for an early visual smoke detection and thusof a beginning fire. According to the invention a fireproof intumescentmaterial is positioned inside of the enclosed second space along theflow passage gap or leak so that the flow passage, gap or leak remainstemporarily unobstructed when a fire has started for smoke to escape andthus to be detected. The fireproof intumescent material does not yetexpand at temperatures at which smoke is generated, but it does expandwhen the fire is generating a temperature corresponding to or exceedingthe response temperature of the fireproof intumescent material, wherebythe expanding fireproof material enters into the air flow passage leakor slot for substantially airtightly sealing any air flow passage or airflow passages and thus preventing air and oxygen from entering into theenclosed space for smothering the fire.

[0019] According to the invention the fireproof or fire-resistantintumescent material is so positioned that at least its initialexpansion is controlled or rather directed, for example by a guidesurface into the air flow passage, gap or leak so that these openingsare substantially completely filled and thus sealed with the intumescentmaterial. When the intumescent material is installed in a grooveextending alongside the openings the lateral groove walls act as a guidesurface at least at the beginning of the expansion, particularly whenthe groove is not completely filled with intumescent material.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order that the invention may be clearly understood, it willnow be described in connection with example embodiments and withreference to the accompanying drawings, wherein:

[0021]FIG. 1 is a perspective view of a passenger aircraft overheadluggage compartment with an air gap for initial smoke escape accordingto the invention;

[0022]FIG. 2 is a schematic sectional view along section line II-II inFIG. 1;

[0023]FIG. 3 is a view similar to FIG. 2 showing an installation of theintumescent material in a groove extending alongside of the airflow gap;

[0024]FIG. 4 is a sectional view through two abutting container wallsections;

[0025]FIG. 5 shows a perspective view of a food container for anaircraft equipped according to the invention with intumescent materialor strips;

[0026]FIG. 6 is a sectional view of two container walls forming acorner;

[0027]FIG. 7 shows a perspective view of a freight container toillustrate where air leaks can occur; and

[0028]FIG. 8 is a sectional view along section line VIII-VIII in FIG. 5.

DETAILED DESCRIPTION OF A PREFERRED EXAMPLE EMBODIMENT AND OF THE BESTMODE OF THE INVENTION

[0029]FIG. 1 shows an overhead luggage compartment 1 with a lid 2 and awall 3 forming a compartment box or bin. According to the invention adefined slot 4 is provided in the wall 3 of the compartment 1.Preferably, the slot 4 is provided along a short portion of a bottomedge where the lid 2 in its closed state does not contact the bottomedge of the bin to permit smoke to escape through the slot.

[0030] The slot 4 assures that smoke generated by a beginning fire inthe compartment 1 can be visually detected as the smoke exits throughthe gap 4.

[0031]FIG. 2 shows that a hinge 5 secures the lid 2 to the compartmentwall 3 of the compartment 1. The lid 2 is shown in a closed condition toillustrate the position of the gap 4. According to the inventionintumescent fireproof or fire resistant material 6, for example in theform of an adhesive strip, is positioned inside the enclosed space ofthe compartment 1 alongside and in parallel to the gap 4 and along anyother leak that may exist. The intumescent material 6 may be adhesivelybonded to an inwardly facing edge 8 of the compartment wall 3. A guidesurface 7 such as a sheet metal strip or the like makes sure thatexpansion of the intumescent material 6 is directed at least when theexpansion begins, into the gap 4 to substantially completely seal thegap 4 if the temperature inside the compartment 1 has risen above anexpansion response temperature of the intumescent material 6.

[0032]FIG. 3 is a view similar to that of FIG. 2, however theintumescent material 6 is installed in a groove 9 of the compartmentwall 3 next to the gap 4. The guide surface 7 again makes sure that theintumescent material expands into the gap. In both instances, namelyFIG. 2 and FIG. 3, the gap 4 prior to the expansion of the intumescentmaterial 6, remains open so that smoke can escape and thereby be seenoutside of the compartment 1. In FIG. 3, the guide surface 7 may not benecessary if the groove 9 is not completely filled with intumescentmaterial 6. In that case the side walls will guide the expandingmaterial into the gap 4 at least initially when the expansion begins.

[0033] The same consideration applies to the installation of theintumescent material in a food container FC shown in FIG. 5 or a goodscontainer GC shown in FIG. 7. In all instances the intumescent materialis installed in parallel to and alongside any gaps and leaks forming airflow passages 12 in the containers FC and GC. Such air flow passages 12may occur in the food container FC around the door D and where containerwall sections 10, 11 are joined to each other. The gap 12 is shownexaggerated in FIGS. 4 and 6.

[0034] In FIG. 4 two walls 10 and 11 abut each other, but still providea leak 12 along the wall edges that are conventionally joined to eachother. According to the invention a groove 13 is provided in at leastone of the two abutting walls 10 and 11 and the groove is filled withintumescent material 6, preferably not completely so that the sidesurfaces of the groove 13 facing each other can function at leastinitially for directing the expansion of the intumescent material 6 whenthe required expansion temperature has been generated by a fire in thecontainer FC or GC. Similar considerations apply to FIG. 6, except thatthe walls 10 and 11 form a corner with a leak 12 rather than an in-lineabutment.

[0035]FIG. 8 shows the sectional view along the section plane VIII-VIIIin FIG. 5. A hinge 14 secures the door D to a door frame section 15.Intumescent material 6 is installed, for example in the form of anadhesive strip along the door frame section 15 next to and along thehinge 14. A guide surface 17 assures that the intumescent material 6will expand in the direction toward any leaks that are formed along thehinge 14 to seal this area, preferably completely. A groove 18 isprovided in a further frame section 16. Intumescent material 6 isinserted into the groove 18. Again a guide surface 19 makes sure thatthe initial expansion of the intumescent material 6 is guided ordirected into the gap or leak 12. The door opens outwardly as indicatedby the arrow 20. The guide surface 19 may not be necessary if the groove18 is only partly filled as explained above.

[0036] An important advantage of the invention is seen in that followingthe early discovery of smoke that can escape through the gap 4 or theleaks 12 forming air flow passages, the intumescent material 6 canexpand into the air flow passage as soon as the required heat has beengenerated by a fire in the enclosed space inside an aircraft. As soon asthese air flow passages are sealed by the intumescent material 6, airflow and hence oxygen supply into the enclosed space is stopped or atleast reduced to a substantial extend so that the fire will be smotheredand possibly completely extinguished. This feature of the inventiongreatly facilitates firefighting operations onboard of an aircraft,particularly since a fire that has started in an enclosed space such asa luggage compartment or goods container can extinguish itselfautomatically without any further efforts by the crew. Theseself-extinguishing characteristics of the invention are cost effectiveand hardly add any weight to the total weight of the aircraft.

[0037] The intumescent material is preferably “PALUSOL” (™) manufacturedby BASF AG in Germany.

[0038] Although the invention has been described with reference tospecific example embodiments, it will be appreciated that it is intendedto cover all modifications and equivalents within the scope of theappended claims. It should also be understood that the presentdisclosure includes all possible combinations of any individual featuresrecited in any of the appended claims.

What is claimed is:
 1. A method for detecting smoke and smothering afire in an enclosed space inside an aircraft, said method comprising thefollowing steps: a) providing at least one air flow passage for air toflow into and out of said enclosed space for letting smoke generated bya beginning fire out of said enclosed space for detection outside saidenclosed space in said aircraft, b) installing in said enclosed space afireproof or fire resistant intumescent material next to and along saidair flow passage, said fireproof or fire resistant intumescent materialhaving a characteristic expansion temperature higher than a smokecausing temperature in said enclosed space, and c) heating saidfireproof or fire resistant intumescent material at least to saidexpansion temperature for expanding said fireproof or fire resistantintumescent material into said air flow passages thereby substantiallysealing said at least one air flow passage and minimizing or stoppingair and oxygen access to said enclosed space by expanded intumescentmaterial to smother said fire.
 2. The method of claim 1, furthercomprising forming said at least one air flow passage in said enclosedspace as a defined slot through which smoke can escape for an earlydetection and guiding said fireproof or fire resistant intumescentmaterial, when it expands, into said defined slot from inside saidenclosed space toward the outside of said enclosed space.
 3. The methodof claim 1, further comprising installing said fireproof of fireresistant intumescent material inside said enclosed space in parallel tosaid at least one air flow passage and guiding said fireproof orfireresistant intumescent material, when it expands, into said at leastone air flow passage from inside said enclosed space toward the outsideof said enclosed space.
 4. The method of claim 1, further comprisingselecting said fireproof or fire resistant intumescent material as anadhesive tape having at least one sticky surface and installing saidadhesive tape alongside said at least one air flow passage.
 5. Anaircraft having a body enclosing a first space, an enclosed second spaceinside said first space, an opening into said enclosed second space, aclosure for closing said opening, at least one flow passage forpermitting smoke to pass out of said enclosed second space when abeginning fire generates smoke inside said enclosed second space for anearly detection of said beginning fire, a fireproof intumescent materialinstalled inside said enclosed second space along said at least one flowpassage in such a position that said at least one flow passage remainstemporarily unobstructed for said smoke to escape out of said enclosedsecond space for detection, and wherein said fireproof intumescentmaterial expands into said at least one flow passage in response to saidfire generating a temperature sufficient for expanding said intumescentmaterial into said at least one air flow passage for substantiallyairtightly sealing said at least one flow passage and substantiallypreventing air and oxygen from entering into said enclosed second spacefor smothering said fire in said enclosed second space.
 6. The aircraftof claim 5, wherein said enclosed second space is an overhead luggagebin comprising a lid, a bin wall enclosing said bin, an access openingin said bin wall, said lid normally closing said access opening, a gapforming said at least one flow passage between said lid and an edge ofsaid access opening, and wherein said fireproof intumescent material isinstalled along said edge for substantially airtightly sealing said gapwhen said intumescent material expands.
 7. The aircraft of claim 6,further comprising a guide surface positioned alongside said gap forguiding expanding fireproof intumescent material into said gap.
 8. Theaircraft of claim 6, further comprising a groove in said edge along saidgap, said fireproof intumescent material being installed in said groove,at least one wall of said groove forming said guide surface.
 9. Theaircraft of claim 5, wherein said enclosed second space is a goodscontainer comprising a door opening, a frame surrounding said dooropening, a door for closing said door opening, wherein said flow passageis a gap or leak between said door and said door frame, and wherein saidfireproof intumescent material is installed along said gap or leak forairtightly sealing said gap or leak when said intumescent materialexpands.
 10. The aircraft of claim 9, further comprising a guide surfacepositioned alongside said gap or leak for guiding expanding fireproofintumescent material into said gap.
 11. The aircraft of claim 9, furthercomprising a groove in said door frame along said gap or leak, saidfireproof intumescent material being installed in said groove, at leastone wall of said groove forming said guide surface for said fireproofintumescent material.
 12. The aircraft of claim 9, wherein said goodscontainer further comprises container walls and leaks forming additionalflow passages where said container walls are joined to each other, andadditional fireproof intumescent material installed along saidadditional flow passages for expanding into said additional flowpassages when said fireproof intumescent material is heated sufficientlyfor expanding.
 13. The aircraft of claim 12, further comprising a guidesurface positioned alongside said additional flow passages for guidingexpanding fireproof intumescent material into said additional flowpassages.
 14. The aircraft of claim 12, further comprising a groovealong said additional flow passages, said fireproof intumescent materialbeing installed in said groove, at least one wall of said groove formingsaid guide surface for guiding said fireproof intumescent material atleast when expansion begins.
 15. The aircraft of claim 5, wherein saidfireproof intumescent material is an adhesive tape having at least onesticky surface.
 16. The aircraft of claim 1, wherein said fireproofintumescent material is “PALUSOL” (Trademark).
 17. The aircraft of claim5, wherein said second enclosed space comprises walls with wall edgesalong said at lest one airflow passage, a groove in at least one of saidwall edges alongside said at least one air flow passage, and whereinsaid fireproof intumescent material is installed in said at least onegroove.
 18. The aircraft of claim 7, wherein said groove is partiallyfilled with said fireproof intumescent material so that groove sidewalls guide the initial expansion of said intumescent material into saidat least one air flow passage.